1. Field of the Invention
The present invention provides a means for determining whether a patient has preeclampsia and, more specifically, it provides such a method based upon the elevation of marinobufagenin in a body specimen of a pregnant woman. The invention also relates to a diagnostic apparatus employable in making such determination.
2. Description of the Prior Art
Eclampsia, which is a condition experienced by pregnant women and generally involves coma and/or convulsive seizures during the same period without other etiology. Preeclamnpsia, if untreated, can progress suddenly to eclampsia Eclampsia, which is usually fatal if untreated.
Preeclampsia is generally characterized by the presence of hypertension proteinuria and edema. It is a disorder which generally occurs only in women who are more than 20 weeks pregnant.
Elevated blood pressure or hypertension has long been recognized as a health problem. It is a very common disease which can have widespread effects on a patient's body and frequently, unlike numerous other diseases, is asymptomatic.
Despite known means of measuring blood pressure of a patient as by a sphygmomanometer, for example, there is lacking an accurate reliable means of detecting the presence of volume dependent hypertension involving higher arterial blood pressure by use of a body specimen, such as blood serum or blood plasma.
From a pathogenic standpoint, essential hypertension may be divided into two broad categories: (a) volume expansion hypertension, and (b) vasoconstriction hypertension. It has been estimated that about 30 to 40 percent of human essential hypertension may be permanently related to volume expansion hypertension, especially in certain demographic groups. Previous studies participated in by the present inventor have demonstrated an alteration in the phosphorylation of a proximal tubular membrane protein following acute saline expansion of the experimental rat (Puschett et al. Volume Expansion Induced Changes in Renal Tubular Membrane Protein Phosphorylation, Biochem. Biophys. Res. Commun., 143:pp. 74-80 (1987)).
U.S. Pat. No. 5,770,376 discloses the use of a blood specimen in diagnosing hypertension as an indication of acute myocardial infarction. It employs plasma levels of a marinobufagenin-like immunoreactivity as a marker for hypertension.
U.S. patent application Ser. No. 10/109,203, now abandoned discloses a substantial reduction in phosphorylation or concentration of a specific protein obtained from a body specimen to determine the presence of preeclampsia.
U.S. patent application Ser. No. 09/990,432, now abandoned filed Nov. 21, 2001 in the name of the present inventor, the disclosure of which is expressly incorporated herein by reference, discloses the use of the CLAMP protein in effecting a determination of the presence of chronic volume dependent hypertension.
While there is no hard and fast rule regarding diagnosis of preeclampsia, several standards have been applied. If a pregnant women develops a blood pressure of 140/90, and has edema of the face or hands, and the presence of urinary protein in concentrations greater than 0.3 grams in a 24 hour urine collection, this is generally indicative of the presence of preeclampsia.
There remains, therefore, a very real and substantial need for a method and apparatus for effectively determining the presence of preeclampsia in a pregnant patient.